1. Field of the Invention
The present invention is directed toward a gradient index lens which is modified to reflect light and to focus a corresponding image. Until the present reflector, state-of-the-art uses for gradient index lens were limited to diode to fiber couplings, fiber to detector couplings, fiber to fiber couplings, lens to lens couplings, or focusing and collimating applications. Prior art has been dedicated to minimizing reflections by angling the lens facet or encasing the gradient index lens with an anti-reflection coating. Within the scope of the present unity of invention, the reflector can be easily incorporated to optical devices, and is particularly adapted to encoders, position detectors, or other instrumentation utilizing line gratings.
2. Description of the Previous Art
a) U.S. Pat. No. 3,658,407-Kitano, et. al., discloses an image transmitter composed of optical fibers. The bundles of fibers are arranged neatly whereby the image formed at one end of the bundle is transmitted to the other end of the bundle.
b) U.S. Pat. No. 3,801,181-Kitano, et. al., discloses a gradient index light conductor.
c) U.S. Pat. No. 4,258,978-Cole, discloses an image reversing array utilizing gradient refractive index. Cole contains an array of optical elements with imaging properties in one meridian and light-containment properties in another meridian. Thus, the inversion of the image occurs across the width but not the length of a slit aperture. U.S. Pat. No. 4,258,978 was directed toward the photocopying industry.
d) U.S. Pat. No. 4,462,662-Lama, discloses a lens array composed of at least two distinct groups of fibers having differing gradient index values. Lama teaches the combination of differing gradient index values and radial parameters blended to form the lens array results in uniform exposure along the imaging plane.
e) U.S. Pat. No. 4,639,094-Aono, discloses a gradient index lens system. Aono teaches the cementing together of two gradient index lens manufactured with different gradient indexes. U.S. Pat. No. 4,639,094 argues the combination of the cemented lens reduces spherical aberration.